In digital television broadcasting, not only television show broadcasting services but also so-called data broadcasting services have already been realized (see Patent Document 1, for example). Future introduction of more sophisticated services into digital television broadcasting by taking advantage of the Internet is now being considered.
When more sophisticated services are introduced into digital television broadcasting by taking advantage of the Internet, there will be a need to make measured modifications to the existing broadcast system for digital television broadcasting, so as to secure operations of receiving devices such as the existing digital television receivers, and take the limited broadcast band into consideration.